FIGS. 21 and 22 show conventional optical deflecting devices, respectively, such as those disclosed in Japanese Unexamined Patent Application Publication No. 7-72409.
The optical deflecting device shown in FIG. 21 has a silicon oscillator 103 including integrally formed elements consisting of: a moving plate 100 as a mirror; a frame 101 surrounding therearound; and S-shaped span-bounds 102 for supporting both sides of the moving plate 100 to the frame 101, respectively, thereby allowing the moving plate 100 to tilt around one axis; and this device is constituted to bond the frame 101 onto a glass substrate 105 formed with electrodes, via a spacer 104.
The optical deflecting device shown in FIG. 22 has elements integrally formed of a silicon substrate, consisting of: a mirror portion 110; a mirror outer periphery 111 surrounding therearound; and scanning beams 112 for supporting both sides of the mirror portion 110, respectively, to the mirror outer periphery 111, thereby allowing the mirror portion 110 to be displaced in one axis direction; and the mirror outer periphery 111 is joined to a glass substrate 113.
The glass substrate 113 is formed with: driving electrodes 114 facing the rear surface of the mirror portion; and a gap forming portion 115 for determining a gap between the mirror portion 110 and driving electrodes 114; such that the glass substrate 113 is formed with external lead connecting portions 116 connected to the driving electrodes 114, respectively, outside the mirror outer periphery 111. Covered by insulative coatings 117 are: the surfaces of the driving electrodes 114; and those portions on the glass substrate 113, which are outside the mirror outer periphery 111 and excluding the external lead connecting portions 116.
As shown in FIG. 23, the optical deflecting device shown in FIG. 21 is constituted to tilt the moving plate 100 around an axis comprising the S-shaped span-bounds 102 by electrostatic forces, by applying an electrostatic force between the moving plate 100 and the due electrode on the glass substrate 105, to thereby deflect the reflected light of the light incident on the moving plate 100.
Further, the optical deflecting device shown in FIG. 22 is constituted to tilt the mirror portion 110 around the gap forming portion 115 acting as a fulcrum formed on the glass substrate 113 below the central portion of the mirror portion 110, by applying an electrostatic force between the mirror portion 110 and the due driving electrode 114, thereby deflecting the reflected light of the light incident on the mirror portion 110.